Europhys. Lett.
Volume 61, Number 5, March 2003
Page(s) 579 - 585
Section General
Published online 01 February 2003
DOI: 10.1209/epl/i2003-00134-y
Europhys. Lett., 61 (5) , pp. 579-585 (2003)

Quantum key distribution for continuous variable by means of phase-sensitive nondegenerate optical parametric amplifier

J. Zhang, C. D. Xie and K. C. Peng

The State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-Electronics, Shanxi University - Taiyuan 030006, PRC

(Received 6 May 2002; accepted in final form 12 December 2002)

A new protocol realizing quantum key distribution for continuous variables is proposed, in which the bright entangled EPR beams are produced from a phase-sensitive nondegenerate optical parametric amplifier. Based on randomly changing the operating states of NOPA at the sending station and randomly choosing the phase difference between two modes of EPR beams at the receiving station, the secret key string is established. The application of direct detection system of photocurrents makes the proposed scheme relatively easier to be experimentally demonstrated.

03.67.Hk - Quantum communication.
03.65.Ta - Foundations of quantum mechanics; measurement theory.

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